Keep part of mesh square when applying subdivision surface
Subsurf is very dependent on how your topology flows. When you see an ugly pole that pinches your geometry that's when you got to rethink the topology. Poles are not evil but they are unavoidable as they control the flow of your topology but must be used sparingly, specially in organic or semi-organic surfaces. The pole in your geometry doesn't look right:



I would suggest changing the topology so you get better subdivision. The red lines control the flow and the blue lines reinforce the geometry to crease the edges:



Make sure to clean up triangles; you want all quads when possible.